A conventional liquid cooling device mainly includes a thermoelectric chip, a water block, a water pump and a water cooling radiator. The thermoelectric chip has a cold end and a hot end. The cold end of the thermoelectric chip is in thermal contact with a heat source, such as a CPU. The water block is in thermal contact with the hot end of the thermoelectric chip. The water pump is connected to the water block and the water cooling radiator via a pipe.
However, the conventional liquid cooling device has the following problem: since the thermoelectric chip is in tight contact with the heat source, thus the thermoelectric chip will lower the ambient temperature near the heat source below the room temperature and thus produce dew, but the dew is likely to drop onto the heat source or circuit near the heat source to cause a short circuit in electronic device.